Dial gauge



Feb. -15 1927.

w.B. HUGHES DIALGAUGE Y Filed March 27.1

93:5 2 sheets-she t 1 .#Feb. 1 5, 1927. w. Br'HU'GHEs DIAL GAUGEFilqdmaron 27. 1925-# z'neets-sheetz 26 p .wg 46* 32 "Ptniid' Feb' 1 51627'.

l UNITED STATES I A 1,617,485 PATENTgoEFic-E,

WILLIAM n. HUGHES, or .vvnsixrrmiin Massacnusnrrs DIAL Gnu-GE.

v Application inea Marcha?, 192e. serial No. 627,984.

*of de icate instruments to be not liable to Av destruction by carelesshandling, which will ,be accurata to the limits of measurement usuallyemployed for the nest work and adapted to retainthat accuracy underconditions destructive to the delicate instruments previously employed.A

More particularly the purposesof this invention are to providecushioning means for the measuring mechanism, improved means forindicating and reading the measurementsmade, and improved. ,means formounting the indicating means and the glass cover for rendering'suchindications visible. i

' In the appended drawings, and description, like numerals have beenemployed to indicate like parts.

Figure 1 is a front pleted gauge.A

Figure 2 is a fragmentary view 'of the gauge front shown in Figure 1.

Figure 3 is a rearv lelevation of the gauge with the back of thebodyremoved.

elevation of the com- Figure 4 is a section on line 4--4 in Fig-Y ure 3.

Figure. 5 discloses a vertical section taken on the center line, fromfront to rear, of the gauge shown in Figure 1.

Figure 6 shows a. sectional View on liiie- 6--6 in Figure 5, looking inthe direction of to its .lowestposition the arrows. g

The front elevation of the complete dial gauge embodying invention,iv'enl in Figure 1, shows a dia face 10, an a ]ustab,l e

graduated dial ring 12, a bezel .14, an indi eating hand 16, a handrevolution counter 18, and a reciprocatory contact member 20, 'whichextends right through the gauge body, terminating in a thumb piece 22above a to projection 25 of the gaugebody 26.

Tiie mechanism of the'gauge is best understood from an inspection ofv Fire` 3. It will beseen that the reciprocato con'- tact member 20 carries,a contactv shoe 21, rack 30,- a guide bar 31, a retrieverspring '33, anda rebound cushion spring 34.

The rack 30 engages, and drives, a pinion -reads thelOtli inches, if thehand 16 41. Attached tovpinion 41 is a gear 42 which engages a pinion 43to which is -attached a gear 44 meshing with a pinion 45 on the shaftwhich carries the indicating hand 16. y y

F rom` a consideration of this gear train` -it will be seen that the"movements of the reciprocatory member 20 are multiplied many times intheir transmission to the indicating hand 16. Movements of a thousandtliof anl inch, or less, in member 20,

.will therefore cause a very considerable, and

asilly readable, indication on the gauge The gear motion `orthe handrevolution Lcounter 18 has not been lshown as it involves only a simplereducing gearing so arranged that the counter indicates the number oftimes which the indicating hand 16 has described a complete circle, 'orin other words,

reads in 1000ths, s

To return the indicating hand 16 to zero, and to assist in taking up anylost motion in the gearing train, a -gear 46 is provided, having a shaft'47 upon which a spiral spring 48 is'wound. One end of thisspring 48 issecured to the bearing bracket 49 and the other to the gear 46. When thepinion 45 is driven by the multiplying geark train, it drives the gear46, and winds up the spring 48, this spring presenting a force in thereverse `directio n.-to that produced by the upward movement of thereciprocating contact member 2O and keeping the teeth of all the gearsalways'in contact, eliminating .backlash.I -Spring48 assisted by spring33 also acts to return the-indicating lignd 16 to4 zero, and thevreciprocatory member 20 95 The guide bar 3l is secured rigidl to themember 20 at one end wliileits ot er end entersa guideslot 32 inthegauge body 26. The rack 30 is a sliding fit on the member 20, and issecured against rotation, while permitted limited independent verticalinotion, by the' screw 51 which entersthe slot 52 in the member 20.v

The. guide bar 31 serves, Where joined to the member 20, to ferm aseating shoulder for the rebound cushion'spring 34 and also i to retainthe rack 30 in correct engagement with `the pinion 41. 'l l The reboundspring 34 lis of heavier wire, 110

- and adapted to offer many times `the resist-` ance of spring'l33. Thenormale position of',

aisA

' such were used. Instead of the mechanismv the` rack 30 is, therefore,that shown in Figre 5,`namel with thescrew 51 against the upper endoslot 52.

The indicating hand 16 attains considerable velocity when thereciprocatory member 20 is suddenl released from the object beingmeasure In tgauges of this kind as heretofore constructe a stop has beenrovided to limit the return movement of the indicating hand and stop itat zero. This has been objectionable because, although the mass of theparts is not great, the shock of suddenly stopping the mechanism wasoften sufficient to bend the indicating hand -or cause it to twist onits shaft so as to render the `instrument inaccurate. It wasalsoessential to make the indicating hand as slender and light aspossible, thereb tend' ing to'make the instrument more -di cult to read.I have overcome' these objections by the use of the rebound .spring 34and the movable rack whereby the shock of the rebound is absorbed by thespring as is most plainly seen from Figs. 1 uand 2 in which the rack 30and spring 34- are shownin dotted lines. 1When the indicating hand 16 isresta ing at zero as shown in lig. noted that the rebound spring 34 isfully extended. Fig. 2 shows the positionof the parts after -a readinghas been noted and the object measured suddenlyr'emoved, and atl theinstant when the hand would bring up with a' heavy shock against thezero stop if having to withstand this shock, however, it

Y will be seen that the hand has swung past the zero position and theshock has'be'en absorbed in compressing the rebound s ring 34.l When thehand 16 has been broug t to a cushioned sto the spring V34 again expandsto its normal ength,f bringing the parts to their normal relationshipand the hand 16 to zero as shown in Fig. 1. Thus the spring 34 formssimple and eiective means for cushioning a'nd absorbing the reboundshock, and as the spring 34 has a much greater expansive force than Vtheother springs, as already described, it does not interfere in any'urement/ may all at any point on the gauge face circle'. To provide anadjustment which will enable the zero graduation to be made at any pointin the complete circle of the gauge face I provide a graduated dial ring12 whichA mounted in the bezel 14, and so arrangedthat the bezel andring may be ro" 1, it will be.

. routine.

l body recess 27 atpoints 61. ition of the hand when work .A

. tine threads iisuall tated about the b dy of the instrume/nt. The. 'ndial plate 10 of the instrument is xed and is thus enabled to carry therevolution counter 18, the hand-ofwhich isA mounted on an arborprojecting through an opening in the face of,the dial. If the entiredial were rotatable -instead of only the graduatedj ring 12, it wouldnot be possible to use a revolution counter of this character.

I have also provided an. improved construction for securing therotatable bezel to the instrument body which' permits of ready assembly,provides the desired friction vr mitting of the rotation ofthe bezel wile holding it in whatever position it ma be yimoved to, and which 4isinexpensive an duparticularly dsrable. This constructionis closed inFigs. 4 and 6. y f In the sectional. view Fig. 4, the bezel 1.4 carriesthe crystal 15, and the graduated dial ,ring 12 asan assembled unit.This unit is rotatably secured to the gauge body 26 by means of acircumferential, body recess 27, an internal bezel recess 14 and alocking wire 58. These recesses 14and 27 are `cut in when turnin 1u thegauge body 29 and the bezel 14, nd o not require more tthan the simplestchanges in the ordinary machine v I The bod cut considerably eeper thanthe diameter of the locking Wire 58, but onl suiciently l recess 27 ispreferably wide to permitthe easy entry o the wire inf to the recess.The'bezelreces's 14is of, the same. width as the body Irecess 27 andpreferabl of a depth equal to about one half the iamcter of thewire. The.locking wire 58 is shaped to the chords of a circle. In

mounting the bezel, the 'i glass 15 and the graduated ring 12 are firstsecured thereto..

The locking wire 58 is then placed in the bod lrecess 27 and squeezed-tothebottom' of t is recess, and until the points`59y (caused by themeetingupf the chords to which-the wirehas been j nt) are even with thesurface of the gauge vbody 26. The bezel may now beslipped over thevgauge bod the recess 14l registers with the beze recess 27, whereu onthe locking wire 58, being no longer hel snaps outward so that itspoints 1 59 engage the recess 14 and are held securel1 in such positionb the contact ofthe chor portions with the ottomof the gauge until n Itwin-be seen that this method of itckis at once simple, positive,involves no in dicult machine' work, and leliminates the em loyed,'while thebezel, 'carrying wit it t e aduated dial ring'12, may bevrevolved comp etely if neeessary, and .the'gradnated ring adjustedas maybe desired, without danggrof becommg sep-- arated. from the gauge dy byhandling or vibration. The exterior surface of the bezel 14, may beknurled, if desired.

It is evident that many modifications in Y Where the indications theconstruction of the parts and in the arrangement of the elements may bemade. The particular arrangement of the r train, of the springs, and ofthe gauge ace, is not essential to my invention. In fact iven by thecounter 18 are not required, the entire gauge face may be attached tothe bezel, instead of merely the graduated indicating ring 12 shown.-

It will therefore be plain that many modiications in the elements, andin .their arrangement, may be made@ without departing from the spirit ofmy-invention, or the scope of the appended claims.

What I-claim is:

' 1. In a gauge, in combination, a reciprocatory contact membercontrolled by the work, an indicator, a spring urging theparts to zeroindicating position and a train constructed and arranged alwa s totransmit with uniformly multiplied e ect the motion of the contactmemberto the indicator, said train comprising a rack, positive abutmentmeans limiting relative movement of the rack and contact member in onedirection, and a .spring under stress malntalmng sald abutment meansnormally in en agement so that the rack and contact mem er are con;strained to move as a unit, said spring being yieldable to absorb themomentum of said train and indicator when they are moved to zeroindicating position. p

2. In a dial gauge, a reciprocatory contact member, an indicating`Vhand, connections between said contact member and indicating handcomprising a multiplyinggear train,

a graduated dial and spring cushion means for said hand and gear train,said reciprocatory contact member being movable in one direction bymaterial measured, said gear train multiplying said movement to lenablesmall variations to be indicated at the dialby the indicating hand andmeans ffgr moving the contact member in the opposite direction whendisengaged bythe material,

said spring cushion -means being arranged on the aforesaid reciprocatorycontact mem-l ber to cushion the rebound of said hand.

3. In a dial gauge, a contact member, an indicating hand and amultiplying gear train transmitting movement from said contact member tosaid indicating hand, said,

gear train including a connection which is yieldable in one directiononly for permitting movement of said hand to a point behind zeroposition and said'gear train being constructed and arranged to impose nolimitation on the movement of the indicator away from zero position.

4. In a dial gauge, a recprocatory contact member, an indicating handand a multiplying gear train for transmitting motion from saidcontactmember 'to' said-indicating hand, said gear train including arack mounted for limited sliding movement on said reciprocatory contactmember and a `rebound spring tendingto resist such movement.

5. A micrometer Agauge provided with a stationary dial face, meansacting over a limited area of said dial face for indicating pmeasurements of one degree of ineness, mechanism projecting through saidface for o rating said indicating means,an adjusta le graduated dialring surroundingsaid face to indicate graduations of another degree ofineness, and amovable indicator col operative with said dial ring.

6. In a dial gauge, a pointer, gau e mechanismvfor actuating saidpointer, a ial ring co-operating with said pointer to fprovide anindicator, a body supportin and pro `tecting said mechanism, a crystaformlnga cover for said body and indicator, a bezel retaining saidcrystal and providing ad- 'ustment means for said dial, and a wireocking ring engaging said bezel and body to retain them in relativelyadjustable` relationship.

In testimony ,whereofl I `have aixed my signature to this s cication. pj

LIAM B. HUGHES.

